I think Brian would be devastated if she won.
He didn't look to happy while watching the video and he really didn't seem very emotional about it from what I can remember.
I know Jake had tears in his eyes and I believe Ken and Ted did too when they saw their home videos.

Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, chocolate in one hand, martini in the other, body thoroughly used up, totally worn out and screaming "WOO HOO what a ride!" -- Steve Parker

Oh God.
Tears of pain might just follow if they got stung by a scorpion.

The preview looked so clearly as if theis was the family visit, if it isn't they will finally have done a good job of concealing something.

I think this could be the gross food challenge as you have stated in one of your wild ass guesses.
The gross food is popular with the viewers so they could simply have changed it to an individual competition rather than a trbal one.
Gross food is generally immunity, but there's no reason it shouldn't be reward.